What Is Legionella?

Legionellosis is a collective term for diseases caused by Legionella bacteria including the most serious Legionnaires disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.

Legionella bacteria are widespread in natural water systems, but usually in low numbers. Outbreaks of the illness occur from exposure to Legionella growing in purpose built systems where water is maintained at a temperature high enough to encourage growth (+20°C to +45°C), such as cooling towers, evaporative condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

If conditions are favourable, the bacteria may grow increasing the risks of Legionnaires disease and it is therefore important to control the risks by introducing appropriate measures.